Beverage preparation machine and method of operating a beverage preparation machine

ABSTRACT

A beverage preparation machine is electrically operated and has a control unit, at least one functional unit, and an electric circuit for supplying the functional unit and the control unit with current. The electric circuit has a switch for switching the current on or off, through respective first and second operations of an operating element. The switch has a first switch contact and a second switch contact, which are connected in parallel in the electric circuit. The first switch contact is brought into a closed state by the first operation of the operating element, and assumes an open state after the second operation. The control unit provides a control signal so that the second switch contact is closed after the first operation of the switch and opened after the second operation of the switch.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an electrical beverage preparation machine forthe preparation/dispensing of a beverage, and to a method of operatingsuch a beverage preparation machine.

2. The Prior Art

Electrical beverage preparation machines, for example forpreparing/dispensing coffee, espresso, steam, hot water, hot milk,foamed milk, etc. are part of the basic equipment of many households,restaurants, factories or offices. For practical reasons, such machinesare usually operated so that they are constantly connected to a mainpower supply, generally by a plug, even when there is no need to preparea beverage.

So that beverage preparation machines can be constantly connected to themain power supply, but operated in such a way that minimal energyconsumption is guaranteed at the same time as maximum safety, suchmachines are generally fitted with a switch that can be operated by auser in order to switch the machine on or off as required, i.e. toswitch the (electrical) power supplying the machine on or off, or, ifnecessary to reduce it to a predetermined minimum value.

To date, various designs for switches intended for use in beveragepreparation machines have become known.

Conventional beverage preparation machines generally have an electriccircuit, connectable to a main supply, to which a control unit and oneor more functional units controlled by the control unit are connected,said functional units being intended for carrying out a processperformable by the machine (e.g. grinding coffee, heating water, brewingcoffee, generating steam, recording machine operating data, displayingoperating data and/or the operating status of the machine etc).

In many beverage preparation machines of this type, the control unit isconstantly supplied with power when the electric circuit is connected tothe power supply. A switch is provided to switch the power required foroperating the relevant functional units on and off. In this case, whenthe power supply to the relevant functional unit is switched off, themachine goes into standby mode. As the control unit is constantly beingsupplied with power, the control unit is always ready to carry outcertain functions (for example, monitoring the switch or checkingcertain sensors provided to monitor the operation of the machine, ormonitoring buttons or interfaces that can be influenced by users inorder to operate the machine).

This design has the drawback that the beverage preparation machine isconstantly using power. There is also a certain safety risk, as thecomponents of the electrical systems constantly consuming power couldcause harm or damage, for example as a result of faults occurring ordangerous actions by users. It is therefore disadvantageous to leavesuch a beverage preparation machine unsupervised for a longer period oftime if it is connected to the main supply.

In contrast to the aforementioned design, other known beveragepreparation machines have two switches in their electric circuit: afirst switch (main switch) which when operated can switch on or off thepower for all consumers connected to the electric circuit, i.e. both forthe control unit and for the relevant functional units, and a secondswitch which exclusively switches the power required for the relevantfunctional units on and off.

The aforementioned design has the advantage that the power in theelectric circuit can be completely switched off through appropriateoperation of the relevant switch. On the other hand, there is thedisadvantage of a user confusing the available switches and not usingthe relevant switch for its intended purpose. For example there is arisk that by operating the first switch, a user simultaneously switchesoff the power for the control unit and the functional unit at a timewhen one of the functional units is just carrying out one of theprocesses intended for preparing/dispensing a beverage. The currentcould be switched off at a time when the functional unit is in anoperating mode in which switching off the power is problematical. Forexample, in the case of a functional unit comprising mechanicalcomponents that move when in operation and could become jammed in anundesirable position in the event of a power outage.

SUMMARY OF THE INVENTION

The object of the present invention is to avoid the aforementioneddisadvantages and to provide a beverage preparation machine and a methodof operating a beverage preparation machine which make it possible toachieve the lowest possible power consumption with a high degree ofsafety with means that are simple for the operator to use.

This object is achieved by a beverage preparation machine that comprisesan electrically operated control unit, at least one electricallyoperated functional unit for carrying out a process involved in thepreparation/dispensing of the beverage, and an electric circuit forsupplying the functional unit and the control unit with power/electriccurrent. The electric circuit has a switch for switching thepower/electric current on and/or off. The switch has a first switchcontact, a second switch contact and an operating element that can beoperated by a user. The switch is designed in such a way that through aninitial operation of the operating element, the power/electric currentis switched on and through a second operation after the initialoperation, it is switched off. To switch on the power/electric current,at least one of the switch contacts must be able to assume a closedstate, and to switch off the power/electric current, both switchcontacts must be able to assume an open state.

The invention accomplishes this task in the following manner:

a) The first switch contact and the second switch contact are connectedin parallel in the electric circuit;

b) the operating element and the first switch contact interact in such away that the first switch contact can be brought into the closed stateby the first operation of the operating element and after the secondoperation of the operating element, the first switch contact is broughtinto the open state,

c) the second switch contact can be controlled with a control signalprovided by the control unit in such a way that the second switchcontact is brought into either the closed or open state depending on thecontrol signal,

d) sensing means are present for sensing an operation of the operatingelement, said sensing means interacting with the control unit in such away that the respective operation of the operating unit is registered bythe control unit,

e) the control unit is designed in such a way that the control unitafter the first operation, takes up an operating status in which thesecond switch contact assumes the closed state, and that afterregistering the second operation of the operating element, the secondswitch contact assumes the open state.

This beverage preparation machine has the advantage that the powersupply to the machine can be switched on and off by operating a singleoperating element. A user can therefore simply and conveniently switchit on and off.

As after switching off the power supply, the two switch contacts areopen, the electric circuit of the beverage preparation machine ispower-off after being switched off, even if the beverage preparationmachine is connected to a main supply. In this state, neither thefunctional units nor the control unit receive power. The beveragepreparation machine can therefore be operated in a simple and anenergy-saving manner.

A further advantage can be seen in the fact that operation of theoperating element is monitored by the control unit and, moreparticularly, switching off the current is controlled by the controlunit. By operating the operating element, a user can only directlyinfluence the state (open or closed) the first switch contact assumes atthat moment. If the operating element is operated for a first time inorder to switch on the power, closing the first switch contactguarantees that the control unit is started up, and the control unitattains an operating state in which the current status (open or closed)of the second switch contact is exclusively controlled by the controlunit. If the operating element is then operated a second time in orderto switch off the power, the power in the electric circuit is notimmediately switched off. The control unit only registers this operationand maintains the current flow in the electric circuit throughappropriate control of the status of the second switch contact for aslong as is necessary for the operation of the beverage preparationmachine.

It is therefore not possible for the current flowing in the electriccircuit to be switched off by a user solely by operating the switchwithout control by means of the control unit. This prevents the powersupply to the beverage preparation machine alone being able to beswitched off at an undesirable time. This guarantees a high degree ofoperational safety and improves user-friendliness.

In one embodiment of the beverage preparation machine according to theinvention, the functional unit is controlled by the control unit, andafter first operation, the functional unit can be brought from aninitial state into an operational state in which the functional unit isready to carry out the respective process. Furthermore, after secondoperation of the switch—possibly controlled by the control unit—thefunctional unit is brought into the initial state or into apredetermined rest state before the switch contact is brought into theopen state, thereby switching off the power.

This embodiment has the advantage that the control unit—if the operatingelement is operated in order to switch off the power—can bring thefunctional units of the beverage preparation machine into a state inwhich the power can be switched off without causing further problems,and in a controlled manner. Damage to the beverage preparation machinedue to switching off the power can thus be prevented by suitablespecification of the control unit. In this way, the operating safety isadditionally increased.

In a further embodiment of the beverage preparation machine according tothe invention, the control unit is designed so that during a delayperiod following the second operation, the second switch contact assumesthe closed state and then, on expiry of the delay period, is broughtinto the open state. The delay time can be predetermined on the basis ofexperience values or suitably determined by the control unit dependingon the current operation status of beverage preparation machine. Thismeasure also improves the operating safety and optimizes energyconsumption.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and features of the present invention will become apparentfrom the following detailed description considered in connection withthe accompanying drawing. It is to be understood, however, that thedrawing is designed as an illustration only and not as a definition ofthe limits of the invention.

FIG. 1 shows a beverage preparation machine in accordance with theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now in detail to the drawing, FIG. 1 shows a beveragepreparation machine 1 for preparing/dispensing a beverage or severaldifferent beverages, for example coffee, espresso, steam, hot water, hotmilk, foamed milk and/or another beverage.

Beverage preparation machine 1 comprises an electrically operatedcontrol unit 5 and an electrically operated functional unit 6 forcarrying out one or more processes involved in thepreparation/dispensing of the beverage in question. Control unit 5 andfunctional unit 6 are connected to a power supply 10 comprising aninternal electric circuit 11 and an (external) main supply 12 connectedto electric circuit 11 by way of connections 11.1 and 11.2. A current Iis supplied to electric circuit 11 via main supply 12.

In connection with this it is assumed, for example, that functional unit6 is equipped in such a way that it can carry out several processes whenin operation, for example grinding coffee, heating water, brewingcoffee, generating steam, registering machine operating data, displayingoperating data and/or the operational status of the machine etc.

The aforementioned integration of several functions in functional unit 6is obviously arbitrary and not relevant to the invention. Functionalunit 6 can also be replaced with several different functional units,each of which only covering part of the functions and being separatelyconnected to electric circuit 11.

Electric circuit 11 comprises in a parallel circuit a first switchcontact 20 and a second switch contact 25, said switch contact beingable to be brought into an open or closed state. Accordingly electriccircuit 11 is closed and current I can pass through it when at least oneof switch contacts 20 or 25 is in the closed state, and no currentpasses through it if both switch contacts 20 and 25 are in the openstate.

Switch contacts 20 and 25 are components of a switch 15 that serves toswitch current I on and off. Switch 15 also comprises an operatingelement 16 which a user can influence (indicated by an arrow 16′ inFIG. 1) in order to operate the switch 15, namely by a first measure toswitch the current I on and a second measure to switch the current Ioff.

The way in which operating element 16 is designed is not relevant inthis connection. Within the context of the invention it is onlyimportant that operating element 16 interacts with first switch contact20 in such a way that switch contact 20, through operation of switch15/operating element 16, is brought into the closed state by way of thefirst measure and is brought into the open state by way of the secondmeasure (the effect of operating element 16 on switch contact 20 isrepresented by an arrow 20′ in FIG. 1).

In the present case, it is assumed that operating element 16 is in theform of a mechanically movable button which is operated by a pressuremechanically exerted on the button. However, operating element 16 canalso be designed in another manner, for example in the form of atouch-sensitive element that is operated by touch, or in the form of adevice that can be operated by remote control, or in the form of anotherinterface accessible to a user.

Operating element 16 and switch contact 20 do not have to be designed asseparate units. Switch contact 20 and operating element can also bedesigned as an integrated unit.

Operating element 16 does not act directly on second switch contact 25.The status of second switch contact 25 is controlled by control unit 5and, more particularly, can be changed when control unit 5 is inoperation, for example with the aid of a control signal provided bycontrol unit 5.

In this case, it is assumed that a switching device 26 controllable witha control signal from control unit 5 is present which, depending on thecontrol signal, acts on second switch contact 25 (as represented in FIG.1 by an arrow 25′), in such a way that second switch contact 25 assumeseither the open state or the closed state.

In the present case it is assumed, for example, that switch contact 25in connection with switching device 26 is designed in the form of arelay R, whereby switching device 26 is designed as an anchor of relayR, and this anchor, controlled by control unit 5, is supplied with acurrent in order to bring switch contact 25 into the open or the closedstate.

Second switch contact 25 can, for example, be designed as a closingcontact of relay R, i.e. as a switch contact that assumes the open statewhen switching device 26 (anchor) is without current and assumes theclosed state when switching device 26 is accordingly controlled.

Switch 15 also comprises sensing means 30 that are able to sense anoperation of the switch 15/operating element 16. The sensing means 30are connected to the control unit 5 in order to allow operations of theswitch 15/operating element 16 to be registered by the control unit 5when it is in operation.

In the present case, the sensing means 30 are in the form of a thirdswitch contact which can assume an open state or a closed state, wherebythe third switch contact, on operation of the switch 15/operatingelement 16, exhibits a transition from one of these states to the otherstate (the effect of an operation of the switch 15/operating element 16on the sensing means 30 is shown by an arrow 30′ in FIG. 1).

Depending on the design of the operating element 16, sensing means 30can also be in the form of a sensor which is sensitive to an operationof switch 15: for example, a (suitably arranged, depending on thefunctional mode) pressure-sensitive and/or temperature-sensitive and/ortouch sensitive sensor which on operation of the switch 15/operatingelement 16 exhibits a reaction that can be registered by control unit 5.

As first switch contact 20, conventional switch contacts with differentcharacteristics are suitable: for example an impulse switch contact,i.e. a switch contact, which normally assumes the open state and, onoperation of the switch 15/operating element 16, is brought into theclosed state for a predetermined period of time and then back into theopen state, or a permanent switch contact which is either permanently inthe closed state or permanently in the open state and only exhibits atransition from one of these states into the other state by operatingthe switch 15/operating element 16.

Beverage preparation machine 1 also comprises a connection 40 betweencontrol unit 5 and functional unit 6. Control unit 5 can, when inoperation, transmit data and/or signals via connection 40 to functionalunit 6 and/or receive them from functional unit 6 in order to controlfunctional unit 6 during operation of beverage preparation machine 1.

Beverage preparation machine 1 can be operated as follows:

If beverage preparation machine 1 is connected to main supply 12 but notswitched on, first switch contact 20 and second switch contact 25 assumethe open state and electric circuit 11 is therefore current-free.

To switch on beverage preparation machine 1, a user operates switch15/operating element 16 for a first time. As a result, first switchcontact 20 is closed and control unit 5 brought into an operating modein which control unit 5 provides a control signal which causes switchingdevice 26 to act on second switch contact 25 in such a way that this isbrought into the closed state. Second switch contact 25 remains stablein the closed state insofar as switch 15/operating element 16 is notoperated again.

Power supply 10 is now switched on and control unit 5 and functionalunit 6 can assume normal operation.

Control unit 5 initially actively controls functional unit 6. For thispurpose, control unit 5 can transmit data and/or signals via connection40 to functional unit 6 and/or receive these from functional unit 6 inorder to register the current status of functional unit 6 and possiblyto cause functional unit 6 to execute certain predetermined measures.

Before beverage preparation machine 1 is ready to prepare/dispense arequested beverage, functional unit 6, controlled by control unit 5,must first be brought from an initial status (which is present onswitching on the beverage preparation machine 1) into a predeterminedoperating mode in which functional unit 6 is ready to carry out therequired processes. For example, it may be necessary to initially carryout a functional check, or automatic cleaning of pipes intended for theflow of a liquid or a beverage prepared by beverage preparation machine1, or starting operations of a heating unit until a predeterminedoperating temperature is reached, or other operations.

Under normal circumstances, functional unit 5 finally attains a state inwhich beverage preparation machine 1 is ready to prepare/dispense abeverage and is ready to receive requests by a user (with the aid ofusual means that are not shown in FIG. 1).

To switch off beverage preparation machine 1, switch 15/operatingelement 16 is operated a second time. First switch contact 20 ispresumably designed to assume the open state. The operation of switch15/operating element 16 is sensed by sensing means 30 and thusregistered by control unit 5. Control unit 5 then provides a controlsignal, which causes the switching device 26 to bring second switchcontact 25 into the open state. In this way, electric circuit 11 is madecurrentless by control unit 5.

Before control unit 5 renders electric circuit 11 currentless, controlunit 5 checks the current operational status of functional unit 6. Asalready stated, it is possible that at the time switch 15/operatingelement 16 is operated by a user for a second time, the functional unitis in an operational state in which immediately switching off of thecurrent is undesirable or could even lead to damage. Control unit 5therefore ensures that the current in electric circuit 11 is onlyswitched off when functional unit 6 is in the initial state or at leastin a predetermined “rest state”. A “rest state” in this context is takento mean an operational state in which immediate switching off of currentI is tolerable.

Accordingly control unit 5 ensures—through appropriate control offunctional unit 6—that functional unit 6 goes into the initial state orinto a predetermined rest state before the current I is switched off.

If necessary, control unit 5 controls second switch contact 25 in such away that second switch contact 25 assumes the open state only after adelay time following the second operation of switch 15/operating element16, whereby the delay time is selected so that functional unit 6achieves the initial state or a predetermined rest state before thedelay time runs out.

Control unit 5 assumes a predetermined end state before current I isswitched off. This ensures that control unit 5 is always in a definedoperational state before the current to electric circuit 11 is switchedoff.

In this context, “switch” 15 is not necessarily designed as one physicalunit with a predetermined spatial structure and arranged in its entiretydirectly at electric circuit 11 or integrated into electric circuit 11.In this context, “switch” is also an abstract term designating afunctional group comprising two switch contacts and an operatingelement, whereby it is assumed that the switch contacts and operatingelement each functionally interact in accordance with the invention. Thetwo switch contacts and the operating element can be separatecomponents, which can be arranged at any position spatially. Forexample, the operating element does not have to be mechanically locateddirectly at electric circuit 11. The two switch contacts and theoperating element can comprise several components or be parts of othercomponents that do not necessarily have to be arranged directly at theelectric circuit 11/integrated in the electric circuit 11, but can bearranged anyway in spatial terms. The latter applies, for example, torelay R constituting switch contact 25 in the case of the embodiment ofFIG. 1.

Accordingly, while only a few embodiments of the present invention havebeen shown and described, it is obvious that many changes andmodifications may be made thereunto without departing from the spiritand scope of the invention.

What is claimed is:
 1. A beverage preparation machine, comprising: anelectrically operated control unit; at least one electrically operatedfunctional unit adapted for carrying out at least one process involvedin the preparation or dispensing of the beverage, said functional unitbeing connected to the control unit; an electric circuit connected to apower supply for supplying the functional unit and the control unit withcurrent (I), said electric circuit comprising a switch for switching thecurrent on and off, said switch comprising: a first switch contact; asecond switch contact connected in parallel with the first switchcontact, the second switch contact being controlled by a control signalfrom the control unit to open and close the second switch contact; andan operable operating element adapted to open the first switch contactin a first operation and close the first switch contact in a secondoperation; and a sensing device for sensing the operations of theoperating element, said sensing device being adapted to interact withthe control unit so that each operation of the operating element isregistered by the control unit; wherein the switch contacts are arrangedsuch that the current is switched on when at least one of the first andsecond switch contacts is brought into a closed state, and the currentis switched off only when both switch contacts are brought into an openstate, wherein closing of the first switch contact by the operatingelement causes the control unit to send a signal and close the secondswitch contact, and wherein opening the first switch contact by theoperating element causes the control unit to then open the second switchcontact, which switches off the current.
 2. A beverage preparationmachine according to claim 1, wherein the functional unit is controlledby the control unit and after the first operation of the operatingelement, said functional unit is brought from an initial state into anoperating state in which the functional unit is ready to carry out arespective process.
 3. A beverage preparation machine according to claim2, wherein the control unit is designed so that the second switchcontact assumes the open state after a predetermined delay timefollowing the second operation.
 4. A beverage preparation machineaccording to claim 3, wherein the delay time is determined so that thefunctional unit is moved into the initial state or a predetermined reststate before the delay time runs out.
 5. A beverage preparation machineaccording to claim 3, wherein the delay time is determined so that thecontrol unit assumes a predetermined end state before the end of thedelay time.
 6. A beverage preparation machine according to claim 1,wherein the second switch contact is a relay closing contact.
 7. Abeverage preparation machine according to claim 1, wherein the firstswitch contact is an impulse switch contact or a permanent switchcontact.
 8. A beverage preparation machine according to claim 1, whereinthe sensing device comprises a third switch contact that switchesbetween an open and closed state when the operating element is operated.9. A beverage preparation machine according to claim 1, wherein thesensing device comprises a sensor that senses an operation of theoperating element.
 10. A beverage preparation machine according to claim9, wherein the sensor is pressure-sensitive, temperature-sensitive ortouch sensitive.